Specialist providers like RT Systems offer their own interface versions which are often more user-friendly on Windows 10/11.
Kenwood distributes its programming software strictly through authorized dealers and service centers. It is technically proprietary software. If you are a commercial entity or need guaranteed stability, the best course of action is to contact a local Kenwood dealer to purchase a licensed copy of the KPG-56D package. Kenwood Tk-3107 Programming Software Download